<h1>
  {{title}}
</h1>

<ul>
  <li class="text" *ngFor="let item of items | async">
      {{item.$value}}
  </li>
</ul>

  <div> {{ (af.auth | async)?.uid }} </div>
  <button (click)="login()">Login</button>
  <button (click)="logout()">Logout</button>